1. Field of the Invention
The invention regards a method and a device for producing lenses of optical systems, in particular of microoptical sensor systems and microoptical transmission systems, as well as a microoptical emitter/receiver system which can be produced by the method and the device.
2. Description Related Art
It is known to produce lenses of microoptical systems by pouring a transparent, curable liquid lens material into the desired lens mould. The lenses cast in this manner are then attached to a suitable lens holder together with optoelements, such as light emitters or optical sensors, which are also provided in the microoptical system, and, in doing so, are brought into the desired position relative to each other. In most cases the parts are attached by using adhesives.
When producing miniature lenses, such as the ones used e.g. for focussing beams in miniature light barrier systems, this manner of production causes great difficulties if simultaneously a high quality imaging is required. The microoptical systems have to be produced with great mounting accuracy in order that the desired optical effect, e.g. a beam focussing, may indeed be achieved. Particularly the axial position of the lens relative to the light source or the optical sensor must be met very accurately or must be adapted to the exact curvature of the lens produced. However, a lateral inaccuracy in the position of the lens with respect to the optical axis or a tilting with respect to the optical axis can result in a poor operatability of the manufactured microoptical system.
The attempt is made to solve this problem by undertaking great efforts with respect to measuring in order to maintain a predetermined axial position when glueing the prefabricated lens into the microoptical system. On the other hand, the produced microoptical systems are subjected to intensive quality controls. If a specific result is asked for, only those pieces may be used whose optical properties lie within a narrow margin. This results either in high reject rates, which cause very high costs, or in that the pieces of minor quality are used nevertheless and a poorer optical workmanship has to be accepted.
Especially high-quality miniature light barrier systems in which a plurality of highly accurate lenses are required, cannot be manufactured at justifiable production costs, when customary methods are used and systems of the customary design are produced.